The present invention relates to a combination structure, and in particular to a device combining a two-way valve and an active carbon canister and a fuel tank with this device.
In convention, to resolve the problem of evaporation of fuel gas in the fuel tank of a car, generally, a fuel gas reverting tube is added to the fuel tank. Via the negative pressure in the fuel gas inlet end of the engine, the fuel gas is attracted to return to the gas inlet end of an internal combustion engine, so as to be used by the engine. Thereby the fuel gas cannot vent to outside to pollute the environment
In above-mentioned gas reverting tube, a carbon canister (C/N) is arranged for absorbing evaporated fuel gas. To regulate an expansion pressure of the fuel gas or a vacuum pressure in the tank, a two-way valve is added to the gas reverting tube for the pressure within the fuel tank to maintain the same state as the atmospheric pressure. Besides to prevent an over large expansion pressure of the fuel gas in the fuel tank to induce explosion or deformation of the fuel tank, a bypass valve is serially connected to the gas reverting tube adjacent to the fuel tank. When the fuel tank, two-way valve or the gas reverting tube is blocked, the bypass valve can be opened for releasing the pressure of fuel gas to protect the fuel tank.
Conventionally, the gas reverting tube connected the fuel tank and the gas inlet of the engine is formed by using soft tubes to be connected between the two-way valve and the carbon canister or connected between the two-way valve, the carbon canister and the bypass valve. However, when the longer the soft tubes or the more the soft tubes are, the resistance in the gas reverting tube is greater, so as to reduce the absorption force of negative pressure of the gas reverting tubes. Thereby fuel gas cannot be reused smoothly. Furthermore, the two-way valve, carbon canister and bypass valve have complicated structures so that the manufacturing and assembled processes are time consuming and cost ineffective. Also the soft tubes are easily arranged disordered to occupy a larger space.